Scalping machine control apparatus



March 16, 1948. E. w. MASON I SCALPING MAQHINE CONTROL APPARATUS 4Sheefs-Sheet l Filed luly 25, 1944 N IMI a El www U w a o M n. ,ww/

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Tram/EY' March 16, 1948. E. W. MASON 2,437,829

SCALPING MACHINE CONTROL APPARATUS INVENTR. R B E//o 4/ 'Naso/7 /M gm@NTTOR'NEY March 16, 1948; E. w. MASON SCALPING MACHINE CONTROLAPPARATUS- 4 sheets-sheet 5 Filed July 25, 1944 March 16, 194s. E, W,MASON l 2,437,829

SCALPING MACHINE CONTROL APPARATUS Filed July 25, 1944 4 Sheets-Sheet 4INVENToR. E//f'o/f IM Nason Mci/3%@ Patented Mar. i6, i948 UNH' soALriNeMACHINE ooNTRoL APPARATUS Elliott W. Mason, Spokane, Wash., assigner toAluminum Company of America, Pittsburgh, Pa., a corporation ofPennsylvania Application July 25, 1944, Serial No. 546,538

9 Claims.

This invention relates to machines for scalping ingots and the like, andmore particularly to improved cutter control mechanism therefor.

In United States Letters Patent No. 2,142,736, granted January 3, 1939,there is disclosed a scalping machine embodying an axially movablerotarycutter which is automatically adjusted into cutting positionpreliminary to the cutting operation under control of a gauge or feelermechanism that cooperates with a presented face of an ingot or slab ofmetal to be scalped. In the operation of this type of machine, because alayer of metal of the same thickness is removed from the opposite facesof each ingot, the variations in thickness of ingots nominally of thesame size are reproduced in the scalped ingots. Such thickness variationis undesirable for subsequent rolling operations as it introducesoperational factors into the rolling schedule which the operators mustbe on the lookout to correct. Especially is this so in case liner metalis placed on the top and bottom scalped faces of sheet ingots and rolledtherewith to become bonded to and integral with the base metal core, astypied,

by the rolling of alclad sheet and plate of aluminum alloy. By supplyingingots in scalped condition for rolling that are all of substantiallythe same thickness, uniform spreading of the liner metal on the stickerpass can be effected and roll settings of all roll stands can be preset,and a sheet product of more uniform coating and quality produced withoutdelays incident to adjusting the mill.

Accordingly, a particular object of the present invention is to providea scalping machine of the type hereinabove referred to that is adaptedto` produce scalped ingots of predetermined thickness as measuredbetween opposite scalped faces thereof.

Another object of the invention is to provide in a machine of the typementioned, selectively operable control means for so controlling theadjustable cutter automatically as to produce scalped ingots ofidentical thickness.

A further object of the invention resides in the provision of novelcontrol means for an adjustable cutter effective to protect the cutteragainst overloading in the event the amount of metal required to beremoved thereby from a face of an ingot presented thereto exceeds apreselected thickness.

Still another object is to provide a machine tool of the characterreferred to in which the machine cycle time to produce scalped ingots ofuniform thickness with at least two machined faces is substantiallyreduced.

In the accompanying drawings illustrating the invention,

Fig. 1 is a perspective view of a particular form of machine tool forscalping ingots and the like;

Fig. 2 is an enlarged sectional elevational View of a portion of theaxially shiitable cutter mechanism of the machine tool, shown prior toits movement into cutting relationship with the work piece;

Fig. 3 is an enlarged transverse sectional view of the tool head shownin Figs. 1 and 2;

Fig. 4 is a diagram illustrating the cutting sequence and operatingconditions; and

Fig. 5 is a schematic wiring diagram of the control system.

Referring to Fig. l, the numeral I0 represents an elongated machine toolbed of any suitable construction that is provided with suitable ways IIon which is slidably supported a work clamping xture or carriage I2 forlongitudinal traversing movement. Any suitable driving mechanism may beprovided to impart forward and backward movement to the clamping xture,a well known form of driving mechanism being d1- agrammaticallyillustrated in Fig. 5. It comprises, in general, a worm I3 meshing witha rack I4 extending lengthwise of the carriage I2 and xed to theunderside thereof. operatively connected to the worm I3 through asuitable dierential gear mechanism I5 are two motors I6 and I1, themotor I6 being adjustable in any well known manner to effect forwardfeed of the carriage at a desired rate, and the motor I1 beingreversible and adapted to effect movement of the carriage in eitherdirection at a rapid traverse rate.

The carriage has a normal position adjacent one end of the bed IB forloading and unloading of the work pieces, such as the sheet ingots abovereferred to or the like. In Fig. 1, the numeral I8` represents a sheetingot clamped in position in the clamping xture preliminary to advancemovement thereof past a rotary cutter I9 (Fig. 2) that is carried by atool support or head 20 jutting out perpendicularly from the bed Ill.The flat slab of metal or ingot I8 is supported on edge in an uprightposition on a plurality of supportlng members 2| (Fig. 1) carried by thecarriage I2. The upper edge of the ingot is adapted to be engaged byhydraulically actuated clamping members 22 that are verticallyreciprocable in clamping heads 23. The heads are arranged for verticaladjustment on the face of theupstanding wall portion 24 of the carriage,and they are provided with power actuators 25 for moving them intovarious positions of adjustment. The heads 2'3 are slldably secured tothe wall 24 by suitable means such as T-bolts (not shown) whose headsare disposed in T-slots 26. clamping members 22 may be arranged in sets,and each set controlled by a manual control lever 27, while theactuating mechanisms for the The 3 provided to effect loading andunloading operations of the heavy work pieces. Preferably backup membersor abutments (not shown) are provided on the upright wall 24 againstwhich the rear face of the ingot I8 may rest so that the ingot will beproperly located for clamping and machining. Of course, the clampingmembers are in a raised position when an ingot is being loaded onto thecarriage, and then they are forced downwardly into clampingengagementwith the upper edge of the ingot. After loading, the carriageis advanced to bring the ingot. into a gauging position adjacent to thecutter, but with the forward end of the ingot rearwardly of the cuttingcircle of the cutter.

The cutter I9 (Figs. 2 and 3) is secured to the inner end of a shaft 29which is journalled in suitable roller bearings 30 within a sleeve 32, aspacer ring 3l being disposed between the bearings 35. Sleeve 32 isrecessed at its end adjacent the cutter for the reception of thebearings 30 and the ring SI, and it has attached thereto an end plate 33which secures the bearings against axial shifting in the sleeve. Theinner races of the bearings are engaged by a collar 34 secured to theshaft and shoulder formed integral with the shaft, whereby the shaft isfree to rotate within the sleeve 32 but is held against axial movementwith respect thereto. The sleeve is slotted at 35 and a pin 38 securedto the tool head 20 extends into the slot. This connection holds thesleeve against rotation, but permits it to slide axially for adjustingthe cutter. The outer end of the shaft 29 is operatively connected to adrive motor 3l (Fig. 1) through a plurality of V-type belts 38 and aspline coupling (not shown) which constitute a flexible connectionpermitting relative axial movement of the cutter shaft and the pulley.

As shown more clearly in Fig. 2, a milling cutter of the face orsurfacing type is illustrated and its cutting face is disposed inparallelism with the path of movement of the carriage l2. Normally thecutter is disposed in a back or retracted position and is moved in orforwardly toward the path of carriage travel into predee terminedcutting positions.

To produce ingots with two opposite sides scalped, a scalping operationis performed on one side of the ingot after which the ingot is reversedwith respect to the cutter and the scalping operation repeated.Hereinafter the respective scalping operations are termed first cut andsecond cut. y

Mounted on the tool head 2e is a gauge or feeler mechanism, indicatedgenerally by the numeral 40, that is operable as a gauge to determinethe depth of cut. This mechanism, as illustrated, comprises a feeler iin the form of an elongated bar or rod supported for axial slidingmovement in a hollow casing or housing 42 which, in turn, is mounted indovetail guideways d3 in a bracket 44 suitably secured to the side ofthe tool head. The feeler d! is held against rotation within the housingl152 by means o-f a pin 45 (Fig. 2), and it is adapted to be shiftedaxially by means of a double-acting piston t6 operating in cylinder llsecured to the cuter end of housing 42. The housing 42 'is normallydisposed in a retracted position, and the feeler el is normallyprojected forwardly relative thereto with a shoulder 43 formed thereonbearing against end plate 49 on the housing. The 'feeler 4I extendsthrough plate 49 and on its forward end threadedly carries a cap foradjustment therealong whereby the capped end of the feeler may beadjusted with respect to the face or plane of the cutter. Initially thecap 5i) is adjusted into such a selected relationship with respect tothe face or plane of the cutter that when the outer or exposed face ofthe ingot is contacted by the feeler and the feeler mechanism actuated,the active face of the cutter will be positioned a predetermineddistance a (Figs. 2 and 4) behind the face of the ingot, for removing acorrespondingthickness of metal from the ingot.

The cutter and feeler mechanism are reciprocated in unison by means of acommon drive that comprises a motor 5l which rotates a worm 52 meshingwith a worm wheel 53. A counter shaft having two sections Ell and 55coupled by a, spline connection E6 is rotated by the worm wheel 53,while pinions El and 58 on the shaft sections 54 and 55 mesh,respectively, with racks 59 and S9 secured to the sleeve 32 and feelerhousing 42. IThe cutter and the feeler mechanism are simultaneouslyadvanced until the feeler lll engages the outer face of the ingot, afterwhich continued movement of the cutter and housing causes relativemovement between the feeler and the feeler housing.

This rearward or push-back movement of the feeler lll is utilized toeffect sequential operation of cutter control devices Si and S2associated with the control system for the machine, such devices beinghere illustrated as limit switches. The upper side of the feeler ilwithin the housing carries a cam 6i on which rests a roller B2 carriedby a motion multiplying link 63 that is pivotally mounted at 6d to thefeeler housing. The roller is adapted to be contacted and forcedupwardly by the sloping cam surface 65 of the cam 6I as the feeler ilmoves rearwardly within the feeler housing. The free end of the link 83is engaged at its upper side by a vertically slidable push rod orplunger 66. A guide for the push rod is formed on a bracket B1 securedto the housing 42. Switch Si is mounted on the bracket 6'! with theroller on its operating arm overlying the push rod 65, and switch S2 isadjustably mounted on the bracket 67 with its operating member inposition to be engaged by said roller, as shown in Fig. 2. The upper endof the plunger is provided with an adjusting screw GG for adjusting itslength. As the plunger moves upwardly, switch Si is actuated or trippedto perform its control function of stopping the cutter advance.Itsoperating arm is capable of overtraveling the tripping point, andsuch overtravel is effected by further movement of the plunger, andswitch S2 is subsequently tripped. Thus, tripping of both switches isresponsive to backward movement of the feeler fil. The switch S2 isprovided to serve as a protective device to protect the cutter againstoverloading, as hereinafter pointed out.

It is desirable to retract the feeler d! after it has performed itscontrol function so as to leave the face of the slab unobstructed forthe milling or scalping operation. This is effected by admitting fluidpressure to the cylinder l through conduit 69, and after the cuttingoperation is completed fluid pressure is admitted to the cylinderthrough conduit 'i6 to again advance the feeler to its normal position.Since, as hereinafter described, this feeler retraction is effectedautomatically for each cutting operation and results each time intripping switch S2, the slope of cam surface 65 is designed to require aselected amount of further travel of the feeler after switch Sl istripped before the crest or top of the cam is reached, and it is in thisfurther feeler travel that the rise of the plunger effects overtravel ofthe arm of switch SI and operation of switch S2. A slope of about 30 tothe horizontal has been found practical.

As shown in Fig. 3, means are provided to clampV or lock the cutter inoperating position. The locking means comprises a semi-circular clampingmember 'll arranged to be clamped tightly against the sleeve 32 to holdit against axial movement. One end of the member 1| is securedinposition to the tool head by suitable means such as cap screws 12, whileits other end is merely loosely held by screws i3 to permit slightvertical movement. Normally the sleeve can be slid axially with respectto the clamping member. When it is desired to lock the sleeve againstsuch movement, a lever 'M fulcrurned at 15 to a bracket carried by thetool head is pulled downwardly to apply pressure against extension 'itof the clamping member, thereby forcing the member tightly against thesleeve. An operating cylinder 'll having a double-acting piston 'I8therein is provided to actuate the link, ow of pressure to and from theopposite ends of the cylinder being eifected through conduits 19 andeil.

Because of the importance of providing scalped ingots of identicalthickness as heretofore pointed out, it is not possible merely toduplicate the rst cut for the second cut in so far as control of thecutter position by the same feeler operation of switch ySi is concerned,since to do so, as heretofore has been the case, results in removingsubstantially the same thickness of metal from the faces of the ingotson both cuts. Consequently, the variations in the initial thickness ofthe ingots are reproduced in the scalped ingots. To overcome thisproblem of variable ingots, control of the cutter for all rst cuts iseffected by feeler control of switch Si, whereby the same preselectedthickness of metal will be removed from each ingot. For second cut,however, the cutter is so controlled independently of switch SI that it.is positioned for removing only that remaining thickness of metal as isrequired in order to bring the ingot to the desired thickness. Hence, agreater or lesser thickness of metal may be removed at the second cutthan at the first cut. The cutting sequence and operating conditions areillustrated in Fig. 4 wherein X represents the initial thickness of theingots and Y the desired thickness of the scalped ingots, Z representingthe occasional ingots that may be too thick initially to be scalped withbut two cuts without overloading and possibly damaging the cutterknives.

For the first cut, the cutter and feeler mechanism advance in unisonuntil the f eeler 4| engages the ingot and is relatively pushed back inits housing. Thereby the sloping cam surface 65 is traversed by theroller 52 to force lever 63 and plunger 6s upwardly until switch SI istripped. Actuation of the switch through circuits to be described causesthe drive motor 5| to stop and the cutter clamp to be actuated so thatthe cutter is positioned the distance a behind the ingot. After the cuta thickness of metal b remains to be removed on the second cut to reducethe ingot to the desired thickness Y. It is to be noted that thethickness of metal remaining to be removed will vary in accordance withthe variations in the initial thickness of the ingots. Hence, b may 6 beless than a or it may be greater than a as represented at c.

For the second cut, the switch Sl is rendered ineective or cut out ofthe control circuit and control of the cutter is transferred to acontrol device illustrated in Fig. 2 as switch S3, which is adapted tobe actuated in response to cutter. advance into a position in which thedistance between its active face and the plane of the backface of theingot in the clamping fixture is equal to Y. Switch S3 preferably ismounted on the side of the tool head 20 in aiiXed position and anadjustable operating member 8| is provided therefor in the form of ascrew that is threaded through a plate 82 suitably attached to theunderside of housing 42. Switch S3 is operable to stop and to clamp thecutter; and, since the feeler housing has identical motion with thecutter, switch S3 may be tripped to stop the cutter repeatedly in thesame position without reference to the remaining thickness of the ingotso that with a given adjustment of the operating member 8| the ingotswill be of identical thickness after the second cut.

In order that switch Sl may be rendered ineffective, suitable means suchas a manually operable two-position selector switch or controller CS(Fig. 5) is provided. When the controller is moved to its No. 1position, switch Sl will be operable in the control circuit, but whenthe controller is moved to its No. 2 position, switch SI will be cut outof the control circuit. In its neutral or off position the controllerrenders the entire control system inoperative.

With reference to Fig. 2, it is to be noted that the cutter advance onthe rst cut with SI in circuit will be terminated by feeler actuation ofswitch Sl before screw 8| reaches the control device S3 as indicated bythe dotted line position of the parts. This is because no metal as yethas been removed from the ingot, it being assumed that all ingots are ofan original thickness X, greater than Y (Fig. 4). On second cut with Sicut out of the circuit, advance of the cutter and feeler is effecteduntil the motion is terminated by operation of either switch S3 orswitch S2 dependent upon feeler measurement of the thickness of theingot. During this second cut advance the feeler engages the ingot andis pushed back as before, thereby gauging the thickness of the ingot.Ordinarily switch S3 is tripped before the feeler is pushed back farenough to effect actuation of switch S2. In this connection it ispointed out that it is possible to effect a greater depth of cut onsecond cut than that for which the feeler is set to determine, since, asabove explained, the feeler is required to be moved a selected distancepast the tripping point of switch Sl before switch S2 will be operated.This allows substantial varitions in ingot thickness after the firstside has been scalped to be removed in one pass from the other side ofthe ingot at the second cut. However, in case the second cut thicknessis excessive as indicated by c, Fig. 4, the feeler will cause switch S2to be tripped prior to actuation of switch S3 to set up an emergencyreturn circuit for the cutter and thereby indicate that the depth of cutis too great.

Referring to Fig. 5, the control system illustrat-ed incorporating thecutter control provides automatic cyclic operation of the machine toolfollowing the loading of the ingot in the clamping fixture in itsloading position. The cycle of operation for the first cut cycle willnow be described in detail. First, however, it maybe mentioned that thevarious control circuits will be energized from suitable electric supplylines which for simplification are represented in the drawing by thepolarity symbols positive and negative in a circle and referred to inthe following description as P and N, respectively. In addition to thecutter control devices heretofore mentioned, Si, S2, and S3, a switch S4is associated with the feeler mechanism and is adapted to be actuated bya dog 85 on the housing 42 to terminate retractive movement of thecutter and feeler mechanism. Switches S5, S5, and S'I are associatedwith the traveling clamping fixture for actuation by trip members ordogs 86, 81, and 88, respectively, A 4-way solenoid operated valve SGprovided by means of which fluid pressure from a suitable source issupplied to the pistons G and '53. Solenoid 9| when energized moves theslide element of the Valve (not shown) to the left so that pressure uidflows from pressure line 52 past the valve through common conduit 93 andconduits S3 and 'i9 to clamp the cutter and to retract the feeler awayfrom the face of the ingot. Exhaust is effected at this time throughconduits --l and common conduit 9E past the valve to exhaust line 95.Solenoid 56 pulls the slide element of the valve to the right to reversethe connections, thereby actuating the clamp to release the cutter andprojecting the feeler forwardly into normal position. The slide elementof the valve remains in either of its operating positions until it isshifted to its other position so that the solenoids need be energizedonly momentarily. Contactor switches or relays A5I and REI are providedfor connecting the motor `5I to supply lines LI, A5I when energizedeffecting cutter advance and R5I when energized effecting cutterretraction. Contactor switches or relays All and Ril are provided toconnect the rapid traverse motor I'I to supply lines L2, contactor All'controlling the motor to cause advance of the carriage I2 and contactorRII controlling the motor to eiect return travel of the table I2. Acontactor C5 is provided to connect the feed motor I6 to D. C. supplylines L3. In addition, control relays CRI, CRZ, and CR3 are provided toeiect certain control operations.

With the controller CS in its No. 1 position and table I2 in loadingposition with an unscalped ingot i3 clamped thereon, start switch 91 isdepressed to initiate the first cut cycle, whereby CR3 is energized (Pat CR2-Iilil-9I-CS- IGi-CR3-N). At this time the cutter and the ieelermechanism are in their retracted positions. CR3 energize/s valvesolenoid 95 to insure release of the cutter and. projection of thefeeler in its housing (P at CR-I'--N) and completes a circuit for All'(P at S-IE-SI-IsL-ll- IE--Sli-I-S--Idl-CR3-lG8-Rl'I-AI'I- N). AI l isthus energizedto cause rapid advance of the carriage l2, and it is heldin by closure of its contacts ISS so that the start switch 91 may bereleased and CR3 de-energizes.

The table travels rapidly toward gauging or feeling position and isstopped in such position when adjustable dog 37 on the carriage hitsswitch S5 and opens a point in the above traced circuit for All so thatthe motor Il is disconnected from the line L2. As the table moves awayfrom loading position, dog SS releases switch S5 so that later the tablemay be returned. Switch S6 when actuated by dog S'I also completes acircuit for the A55 contactor whereby the motor 5! is connetted to lineLI and advancing movement is imparted to thecutter and feeler mechanism.A5I is energized through a circuit P at S3-I03-SI led-S'-I Ill-CRI-II6-A5I-I I I -CR2 -N. This circuit remains effective so long as switchSI remains in its normal position. It is to be remembered that SI isactuated in response to push-back movement of the feeler, and when thisoccurs the circuit for ASI is opened whereby advance of the cutter isterminated with the cutter in a cutting position determined by theinitial thickness of the ingot I8. Preferably an electromagneticallyoperated brake (not shown) is operatively associated with the motor 5Iand is actuated upon release of A5I to prevent overtravel of the cutter.

Actuation of switch SI also energizes control relay CB2 (P atS'I--II2-CS-II3-SI-II4 CRI- l I-5-CR2-N) As a result positive is removedfrom conductor ISU so that CR3 cannot be energized and another point inthe circuit of ASI is opened. It also completes a circuit for energizingthe clamping solenoid 9| (P at CR2 IIl-5I-N). Thereby valve 90 isactuated to the left and pressure admitted to the conduits 'I9 and 5Swhich causes the clamp II to be actuated and the feeler 4I to beretracted from the face of the ingot. As a result of the full retractionof the feeler, switch S2 will be actuated, but at this time nothing willhappen because CR2 is energized and there is no positive on the circuit.Closure of switch CRE also completes a circuit P at CR2-I2ll-C5--N) andby energization of contactor C5 the feed motor I6 is connected to thesupply line L3. Thereby feeding movement of the carriage at a desiredslow rate of feed is initiated to move the ingot into contact with andpast the cutter I9. Consequently, the exposed face of the ingot will bescalped, a predetermined thickness of metal being removed. Movement ofthe dog 81 past switch S6 allows the limit switch to return to normalposition, thereby opening another point in the circuit of the cutteradvancing contactor A5I, and closing a point in the circuit for therapid advance contactor AI'I. It is to be noted, however, that AI'Icannot be energized at this time because its original energizing circuitis open at S4, this switch being released by the dog 85 at the start ofthe advancing movement of the feeler mechanism.

Slow feed of the ingot past the cutter continues until the entire lengthof the ingot is scalped, whereupon adjustable dog 88 on the carriagetrips the limit switch S'I. As a result positive is removed from theenergizing circuit of relay CE2 and this relay drops out, therebyopening the circuit for the clamping solenoid Stand opening theenergizing circuit for the contactor C5. Feed movement of the carriageis thus terminated. In addition, operation of switch S1 completes acircuit (P at S'I-I23 CRL-N) for the CRI relay. It may be noticed atthis point that a parallel circuit for the CRI relay extends throughswitch S2 through conductor I24CR2P so that the CRI relay can beenergized independently of the limit switch S1 whenever the controlrelay CR2 is in a de-energized condition.

Energization of CRI opens another point in the circuit of the relay CR2and it completes a circuit for the solenoid (P at CR-I25-I02 S5-N) sothat again the cutter will be released for retraction and the feelerprojected into forward position in the feeler housing. Relay CRI alsocompletes a point in the circuit of the rapid return contacter RI'I butcontactor RI'I will not be energized because the feeler mechanism andthe cutter have not yet been retracted. Such retraction is effected byenergization of the contactor R5! (through a circuit P at SLI-|26-CRI-I2i-R5I-I I I-CR2-N) whereby the motor 5I is connected across theline LI and driven in a direction to retract the cutter.

Retraction is terminated when dog B5 actuates switch Sli to removepositive from the above traced circuit of the contactor R'l. Actuationof switch S4 also completes the circuit for the contactor RI'I (P atSS--IS-SI-l--stop switch S-I--Sii-ll-S-lZS-CRi-l28- RIT-N) Thiscontacter picks up and completes a holding circuit for itself atcontacts ISG so that it will be held in after de-energization of therelay CRI which occurs when dog 88 releases S'I upon retraction f thecarriage. The contacter RII connects the rapid traverse motor H to theline L2 so that the carriage is rapidly returned to its loadingposition. When it reaches loading position further movement is preventedby the dog tripping switch S5, thereby opening the holding circuit forthe contactor RIT which drops out and motor Il is disconnected from theline. This completes the rst cut cycle.

After reversing the ingot in the carriage and reclamping it with itsopposite face exposed for.

scalping, the second cut cycle is initiated. First, the controller CS ismoved from its No. 1 position to its No. 2 position and then the startswitch 91 is momentarily depressed. The same cycle of operation asheretofore described will take place except that by reason of movementof controller CS to its No. 2 position, control of the cutter advance iseffected by means of switch S3 instead of SI. The normally closedcontacts of switch SI are shunted by a circuit extending through thecontroller, the shunt circuit extending from conductor HB3 throughISI-CS--ISZ to a common point between stop switch S8 and open contactsof switch SS. Therefore, when the cutter and the feeler are beingadvanced, such advance will continue until the operating member 8l tripsswitch S3 to open the circuit of the cutter advancing contacter ASI(this circuit is P at S3-Ii13--I3I--CS-I32-S'-Ilil- CRI-I Iii-A5 I I Il-CR2--N) Also, since the selector switch cuts out the circuit extendingthrough the normally open contacts of switch SI, relay CRZ will not beenergized by operation of switch SI, but only by operation of switch S3(through a circuit P at SI-ISS-SS--IM-I I4- CRI-I I5--CR2-N). Hence, thefeeler mechanism and the cutter may be advanced beyond the point atwhich switch SI would normally be actuated by push-back of feeler 4I.Thus, when switch S3 is actuated, advance of the cutter is terminatedwith the active face of the cutter spaced a preselected distanceawayfrom the plane of the rear or previously scalped face of the ingot,the cutter clamp is actuated, and slow feed of the ingot past the cutteris initiated. v After the cut is completed, the cutter clamp isreleased, the cutter is retracted, and the table is rapidly returned tonormal position in the same manner as heretofore described. The secondcut cycle is thereby completed with the ingot scalped to a selecteddesired thickness.

As heretofore explained, the thickness of metal to be removed on thesecond cut may be excessive and cause the switch S2 to be actuatedduring push-back of the feeler 4I before switch S3 is actuated. As aresult a safety circuit to return. the cutter is completed '(P atCB2-i244 S2'-CRI-N), CR2 being de-energized at this time because thefeeler and cutter are advancing. At this time relay CRI operates tocomplete the heretofore traced circuit for the cutter return controlrelay RSI. It also opens a point in the circuit of the contactor ASI.VAs a result R5I picks up and AEI drops out and the f cutter begins toretract. During this retraction of the cutter and the feeler housing,the

plunger B5 will descend and allow the switch S2 to open. Thereby therelay CRI is de-energized so that R5I drops out and A5I again picks upto effect advancement of the cutter. Naturally the operations will againrecur whereby an` oscillating motion will be imparted to the cutter.This indicates to the operator that the thickness of the metal to beremoved is too` great to be removed at one cut. He will return thecontroller CS to its No. 1 position, thereby allowing the cutter to bemoved under feeler control to aposition in which it will remove a tocompletion.

troller will be moved to No. 2 position and the second cut cycle ofoperation effected on the in-- got to remove the remaining metal toreduceitfto' the desired thickness Y.

From the foregoing it will be Vseen that se-l quentially operativecutter control mechanismhas been provided for automatically scalpingingots of Varying nominal thickness to a uniform' thickness. While aparticular embodiment of the invention has been illustrated, it will beunderstood that various equivalent means may be substituted for thosespecically disclosed herein and l variations in the particular systemdisclosed employed without departing from the spirit of the invention orthe scope of the appended claims.

What is claimed is:

1. In a machine tool of the type described, a;

rotary cutter, a feeler associated therewith, power means for movingsaid cutter and said feelerA in unison toward a work piece disposedforward-V ly thereof but outside the circle described by saidl cutter,said feeler being adapted to engage the outer tace of said work piecewhereby its forward motion is terminated while said cutter continuesV toadvance relative to said feeler into a cuttingl position behind theplane of the outer face of said work piece, control means operablerespon sively to said relative movement between said` cutter and saidfeeler for stopping said power,A means with said cutter in a feelerdetermined. positionwith respect to said outer face vof said.

work piece, control means responsive solely to cutter advance forstopping ,said power vmeans; with said cutter in a fixed distancerelation with, respect to the inner face of saldwork'p'iece, and.

means for rendering each of said control means operable alternately inthe order namedin a rstL cut and a second cut sequence on opposite faces,Y

of said work piece respectively.

f2. In a machine tool of the type descrlbedpa rotary cutter, a feelerassociated therewith, re-.

versible power means for moving said cutter and said feeler in unisontoward a work piece dis-l into' a cutting Vposition behind the plane ofthe' outer faceofsaid workpiece, control means operable responsivelytosaid relative movement hetween said cutter and said'feeler for stoppingsaid power means with said cutter in a feeler determined position withrespect to said outerr face of said work piece, other control meansresponsive solely`to cutter advance for `stopping said power means withsaid cutter in'a xed distance relation with respect to the inner faceofsaid work piece, means for rendering "each of said control meansoperable ina first cutand a second cut sequence, anda third controlmeans actuated by said feeler in' responseeto said relative cutter andfeeler movement in excess of apreselected extent for rendering saidcutter inoperative.

3.'In apparatusfor scalping opposite sides of aningo't or the like in afirst cut and asecond cut sequence,V in combination, aningot support, apower driven cutter, means for relatively translating said support andsaid'cutter past each other to effect a scalping operation; reversiblepower means by whichsaid cutter is bodily advanced for adjusting itscutting position relative to said ingot for each scalping operation, afeeler engagea-ble with saidfingot during said cutter'advance andadapted for push-back movement reiative'to said cutter, a control devicefor said power means actuated by said feeler responsively tosaidpush-back movement to discontinue advance of the cutter with said cutterpositioned to remove a layer of metal of predetermined thickness fromsaid ingot for said first cut, means for rendering said control deviceinoperative for subsequent advance of the cutter into position for thesecond cut, control means for said power means actuated in response tosaid subsequent cutter ad vance to interrupt the latter when the cutterreaches a position in which the distance between its active face and theplane of the back face of said ingot is equal to a predetermined ingotthickness, whereby on second cut a layer of metal will be removed equalto the difference between said predetermined ingot thickness and thethickness of the ingot remaining after the first cut, and feeleractuated means operable upon pushback movement thereof a preselectedextent past the point at which it normallyV actuates said control devicefor reversing said power means to effect withdrawal of said cutter inthe event said feeler actuated means is actuated prior to actuation ofsaid cutter control means.

4. In apparatus for scalping ingots and the like in a first cut and asecond cut sequence for opposite sides thereof, in combination, asurfacing cutter, an ingot clamping fixture having a loading stati-onand a gauging station at one side of said cutter, means for translatingsaid fixture from said loading station to said gauging station, powermeans for moving said cutter transversely into cutting position, feelermeans associated with said cutter for engaging the exposed side of theingot in said gauging station during power movement of said cutter,alternate control means for said power means responsive, respectively,to actuation of said feeler after said engagement with said ingot, andsolely to said movement of the cutter, whereby said cutter isselectively positioned in either a first cut or a second cut operatingposition automatically, selector means for selectively rendering one orthe other of said control means operative, and means rendered operableby actuation of either of said control means for locking said cutter inoperating position and initiating movement of said clamping 12 fixturefrom 'said gauging station, to carry the ingot past said cutter.

5. In a machine tool of the type described, the combination of a Atoolhead, a rotary cutter mounted thereon for axial shifting movement, a

feeler mechanism slidably mounted on said tool head for movementparalleling that of said cutter, said mechanism including a housing anda feeler movably supported therein and normally in forwardly projectedposition with its outer end disposed in preadjusted relation relative tothe active face of said cutter, common drive means for simultaneouslyadvancing said feeler mechanism and said cutter toward a work piecedisposed forwardly thereof in position to be engaged 4by said feeler butoutside the circle described by said cutter, whereby said feeler afterengaging said work piece is relatively pushed back in said housing whilesaid cutter and said housing continue to advance, a first control devicefor said drive means mounted on said housing, a cam on said feeler,means actuated by said cam upon said push-back movement of said feelerfor operating said control device, to stop said advance with said cutterlocated to remove a measured thickness of metal from said work piece,another control device for said drive means mounted on said tool head,an adjustable operating member carried by said housing for actuatingsaid other control device, to stop said cutter advance with the cutterspaced a predetermined distance from the rear side of said work piece,and means for rendering said first control device inoperative when saidother control device is utilized to control the position of said cutter.

6. In a machine tool of the type described, the combination of a toolhead, a rotary cutter mounted thereon for axial shifting movement, afeeler mechanism slidably mounted on said tool head for movementparalleling that of said cutter, said mechanism including a housing anda feeler movably supported therein and normally in forwardly projectedposition with its outer end disposed in preadjusted relation relativet-o thev active face of said cutter, common drive means forsimultaneously advancing said feeler mechanism and said cutter toward awork piece disposed forwardly thereof in position to be engaged by saidfeeler but outside the circle described by said cutter, whereby saidfeeler after engaging said work piece is relatively pushed back in saidhousing while said cutter and said housing continue to advance, andmeans for controlling the operation of said drive`means during saidadvancing movement comprising a iirst control device mounted on saidtool head in a fixed position'and second and third control devicesmounted on said housing, an adjustable operating member on said housingfor actuating said first control device, a cam on said feeler having asloping cam surface, lever means having a roller for traversing said camsurface upon said relative pushback of said feeler for actuating saidsecond and third control devices sequentially, dependent upon the extentof said feeler push-back, said second control device being effective tolocate said cutter in position for removal of a predetermined thicknessof metal from the work piece for the rst cutting operation thereon, saidrst control means being eifective to locate said cutter in a positionspaced a predetermined distance from the rear side of the work piece,for the second cutting operation thereon, and means for transferringcontrol from said second control device to said first and third controldevices for said second cutting operation, said third control devicebeing operable to effect withdrawal of said cutter in the event it isactuated prior to actuation of said first control device.

7. A machine for scalping ingots and the like in which a cutter isadvanced from a retracted position under control of a feeler actuatedcontrol device thfat advances in unison with the cutter until the ieelerengages the outer face of an ingot to be scalped and thereafter eiectsoperation of said control device to terminate the advancing movementwith the cutter located a predetermined distance behind said outer faceior removing a corresponding thickness of metal from said ingot duringsubsequent movement thereof past said cutter, after which the ingot isreversed so that its opposite face may be scalped, characterized by thecombination with said control device, of means for rendering itineffective prior to scalping said opposite face of the ingot, and meanscontrolled by said cutter and rendered effective by operation of saidlast named means for terminating advance of said cutter when it reachesa preselected position spaced a xed distance away from the rear face ofsaid ingot, whereby after scalping said opposite face the ingot will beof a predetermined thickness, said last named means comprising a secondcontrol device mounted in fixed position relative to forward travel ofthe cutter, and an operating member movable in unison with said cutterfor actuating said second control device.

8. In a machine for Scalping ingots and the like wherein a cutter and afeeler advance simultaneously until the feeler engages the outer face ofan ingot to be scalped whereupon a control device associated with thefeeler is actuated by the feeler to terminate said advance with theactive face of said cutter located a predetermined distance behind saidface of the ingot for removing a corresponding thickness of metal fromthe ingot during subsequent movement thereof past said cutter, afterwhich the ingot is reversed so that its opposite face may be scalped,the combination with said control device, of a second control device forsaid cutter mounted in a fXed position relative to forward travel of thecutter vand operable to terminate cutter advance with the active face ofsaid cutter spaced a predetermined distance from the rear face of saidingot, an adjustable operating member movable in unison with said cutterfor actuating said second control device, switching means effective totransfer control of the cutter from said feeler actuated control deviceto said second control device, whereby positioning of the cutter forscalping said opposite face of the ingot is controlled by said secondcontrol device, means responsive to actuation of either of said controldevices for clamping said cutter in its respective cutting positions,and for initiating movement of the ingot past said cutter, and meansactuated by overtravel of said feeler after its engagement with saidopposite face of the ingot for preventing operation of said last namedmeans.

9. In a machine for scalping ingots and the like, a rotary surfacingcutter, means for advancing the cutter from a retracted position into aforward cutting position for each scalping operation on an ingot,clamping means for said cutter, electrical control means including afirst and a second control switch for stopping said advancing means andactuating said clamping means, means for actuating said iirst switch tostop and lock said cutter in a iirst cutting position with respect tothe outermost face of said ingot, means for actuating said second switchonly after said cutter is advanced past said rst cutting position tostop and lock said cutter in a second cutting position spaced a'xeddistance away from the rear face of said ingot, and switching meanseiective for rendering each of said switches operable alternately in arst cut and a second cut sequence on opposite faces of said ingot,respectively, said ingot being reversed after scalping of one facethereof to present its opposite face outwardly for scalping.

ELLIOTT W. MASON.

REFERENCES CITED UNITED STATES PATENTS Name Date Rougemont Jan. 3, 1939Number

